<!DOCTYPE HTML>
<html class="reftest-wait">
<head>
<script>
function doTest() {
  var c = document.getElementById("c");
  c.style.top = "20px";
  document.documentElement.removeAttribute("class");
}
window.addEventListener("MozReftestInvalidate", doTest, false);
</script>
</head>
<body>
<canvas id="c" style="position: absolute; top:0; opacity:0.5; border:1px solid black; width:200px; height:200px;"></canvas>
</body>
</html>
